The present disclosure relates to an endoscopic camera head.
In the related art, endoscopic devices are known in the medical field as devices for observing the inside of a patient's body cavity. In general, an endoscopic device primarily includes an endoscope having a narrow insertion unit that is inserted into a patient's body cavity, a light source device that supplies the insertion unit with illuminating light that shines onto a target of observation from the tip of the insertion unit of the endoscope, a camera head removably connected to the base of the endoscope, a control device that controls the driving of the camera head, and a display device that displays a captured image.
At the tip of the insertion unit of the endoscope, an illumination window that shines illuminating light onto a target of observation and an observation window that takes in light (observation light) reflected from the target of observation due to the illuminating light are provided. In addition, at the base of the endoscope, an eyepiece with an attached eyepiece lens is provided. Inside the lens barrel of the endoscope, an image guide for observation light is laid out from the observation window at the tip of the insertion unit to the eyepiece at the base of the endoscope. Observation light taken in from the observation window is guided by this image guide to the eyepiece at the base of the endoscope.
The camera head is attached to the eyepiece at the base of the endoscope. Inside the camera head housing, an image sensor and an optical system for condensing observation light onto the image sensor are provided. On the connecting face of the camera head that connects to the eyepiece of the endoscope, an opening for taking observation light into the housing is provided, and a cover glass is disposed on this opening. Observation light enters the camera head housing from the eyepiece of the endoscope through the cover glass, and is condensed onto the image sensor by the optical system provided inside the housing.
By appropriately transmitting a driving signal from the control device to the image sensor of the camera head, the driving of the image sensor is controlled, and an image of the target of observation is captured by the image sensor. The control device performs various types of signal processing on an image signal corresponding to the image of the target of observation captured by the image sensor (captured image) for display of the captured image on the display device. Under control by the control device, the captured image is displayed on the display device on the basis of the image signal that has been subjected to various types of signal processing.
In an endoscopic device having such a configuration, various technologies are being developed to improve the quality of the captured image. For example, JP 2005-66129A discloses technology that uses optical signals to exchange signals such as a driving signal and an image signal between a circuit that comes into contact with the patient (patient circuit), such as the camera head, and all other circuits (secondary circuit), such as the control device, thereby making it possible to electrically insulate the patient circuit and the secondary circuit from each other, while also obtaining a high-quality captured image.